1. Field of the invention:
The present invention relates to a floor panel mounted on an already existing, supporting floor, for acoustic insulation purposes.
2. Background of the invention:
U.S. Pat. No. 3,476,634 (FLEISCHMANN) issued on Nov. 4th, 1969, proposes an acoustically and thermally insulating floor structure designed to cover an already existing, supporting floor. More specifically, FLEISCHMANN interposes a layer of semi-rigid polyurethane foam between the supporting floor and a wooden floor covering.
The floor structure of U.S. Pat. No. 3,476,634 presents the following drawbacks.
Prior to manufacturing and assembling the floor structure, it may be necessary to treat the wood sections, segments, fingers etc. of the floor covering by immersing the same into a hot mineral oil solution, to thereby prevent warping of the wood during the hot curing of the chemical, polyurethane foam.
The layer of semi-rigid polyurethane foam is not glued nor otherwise adhered to the supporting floor. This results into a lack of adherence of the layer of polyurethane foam to the supporting floor, which lack of adherence causes after a certain time warping of the wooden floor covering even if the wood has been treated as described above by immersion in a hot mineral oil solution.
The polyurethane foam used by FLEISCHMANN can crumble and is not flexible enough to stop acoustic vibrations caused by aerial sounds as well as by impact noise. Indeed, it forms a structural interconnection for the transmission of such aerial sounds and impact noise, mainly in the range of frequencies lower than 1 kHz. However, interesting results can be obtained regarding heat insulation, and regarding acoustic insulation for aerial sounds and impact noise at higher frequencies.